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INFO: rcu detected stall in sys_renameat

Status: upstream: reported syz repro on 2024/04/13 20:17
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+37400127ba053f5eb9ed@syzkaller.appspotmail.com
First crash: 20d, last: 20d
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2024/04/14 upstream (ToT) 7efd0a74039f C [report] BUG: workqueue lockup

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3842/1:b..l P4244/1:b..l
	(detected by 1, t=10502 jiffies, g=4621, q=247 ncpus=2)
task:udevd           state:R  running task     stack:0     pid:4244  ppid:3842   flags:0x00000004
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6558
 preempt_schedule_irq+0x8c/0x1b8 kernel/sched/core.c:6870
 arm64_preempt_schedule_irq arch/arm64/kernel/entry-common.c:265 [inline]
 __el1_irq arch/arm64/kernel/entry-common.c:474 [inline]
 el1_interrupt+0x4c/0x68 arch/arm64/kernel/entry-common.c:486
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581
 __do_sys_getcwd fs/d_path.c:432 [inline]
 __se_sys_getcwd fs/d_path.c:411 [inline]
 read_seqbegin_or_lock+0x0/0x250 fs/d_path.c:411
 d_absolute_path+0x13c/0x27c fs/d_path.c:233
 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline]
 tomoyo_realpath_from_path+0x24c/0x4cc security/tomoyo/realpath.c:271
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path2_perm+0x284/0x894 security/tomoyo/file.c:922
 tomoyo_path_rename+0x184/0x1dc security/tomoyo/tomoyo.c:287
 security_path_rename+0x154/0x1f0 security/security.c:1217
 do_renameat2+0x754/0xe64 fs/namei.c:5016
 __do_sys_renameat fs/namei.c:5069 [inline]
 __se_sys_renameat fs/namei.c:5066 [inline]
 __arm64_sys_renameat+0xc8/0xe4 fs/namei.c:5066
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
task:udevd           state:R  running task     stack:0     pid:3842  ppid:1      flags:0x00000004
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6558
 preempt_schedule_common+0xf4/0x1e8 kernel/sched/core.c:6727
 preempt_schedule+0x64/0x84 kernel/sched/core.c:6751
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xa8/0xac kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up_sync_key+0x124/0x1ac kernel/sched/wait.c:208
 sock_def_readable+0x150/0x278 net/core/sock.c:3304
 __netlink_sendskb net/netlink/af_netlink.c:1273 [inline]
 netlink_sendskb+0x98/0x154 net/netlink/af_netlink.c:1279
 netlink_unicast+0x320/0x898 net/netlink/af_netlink.c:1367
 netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x55c/0x848 net/socket.c:2514
 ___sys_sendmsg net/socket.c:2568 [inline]
 __sys_sendmsg+0x26c/0x33c net/socket.c:2597
 __do_sys_sendmsg net/socket.c:2606 [inline]
 __se_sys_sendmsg net/socket.c:2604 [inline]
 __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2604
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
rcu: rcu_preempt kthread starved for 10507 jiffies! g4621 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:0     pid:16    ppid:2      flags:0x00000008
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6558
 schedule+0xc4/0x170 kernel/sched/core.c:6634
 schedule_timeout+0x1d8/0x344 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2cc/0x1538 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xc0/0x308 kernel/rcu/tree.c:1905
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 4344 Comm: syz-executor.2 Not tainted 6.1.86-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
pc : _raw_spin_unlock_irqrestore+0x58/0xac kernel/locking/spinlock.c:194
lr : __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
lr : _raw_spin_unlock_irqrestore+0x48/0xac kernel/locking/spinlock.c:194
sp : ffff80001ebe7330
x29: ffff80001ebe7330 x28: dfff800000000000 x27: ffff80001ebe7400
x26: ffff0000ce6cef00 x25: ffff0000ce6cef00 x24: 0000000000000001
x23: ffff0000cde40018 x22: 0000000000000000 x21: ffff0000cde40000
x20: ffff0000ce6ceec0 x19: 0000000000000000 x18: 1fffe00019cd9d7e
x17: ffff80001583d000 x16: ffff800008305ec4 x15: 00000000200fe000
x14: 1ffff00002b080b0 x13: dfff800000000000 x12: 0000000000000003
x11: 0000000000ff0100 x10: 0000000000000003 x9 : 0000000000000080
x8 : 00000000000000c0 x7 : ffff8000082dc99c x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000006 x1 : ffff8000122ac6e0 x0 : ffff80019ebe8000
Call trace:
 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
 _raw_spin_unlock_irqrestore+0x58/0xac kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 prepare_to_wait_exclusive+0x1bc/0x214 kernel/sched/wait.c:291
 unix_wait_for_peer+0x138/0x2a8 net/unix/af_unix.c:1436
 unix_dgram_sendmsg+0xd90/0x16c0 net/unix/af_unix.c:2043
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x55c/0x848 net/socket.c:2514
 ___sys_sendmsg net/socket.c:2568 [inline]
 __sys_sendmmsg+0x318/0x7d8 net/socket.c:2654
 __do_sys_sendmmsg net/socket.c:2683 [inline]
 __se_sys_sendmmsg net/socket.c:2680 [inline]
 __arm64_sys_sendmmsg+0xa0/0xbc net/socket.c:2680
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/13 20:16 linux-6.1.y cd5d98c0556c c8349e48 .config console log report syz [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: rcu detected stall in sys_renameat
* Struck through repros no longer work on HEAD.